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We encourage chief information officers (CIOs) to play more active roles in organizational level strategy making in the digital era and examine how CIOs could lead their organizations’ digital innovation initiatives. We propose that it is the CIO’s effectiveness in issue selling (i.e., the acts that are directed toward affecting top management teams’ (TMT) attention to and understanding of strategic issues), rather than his or her structural position, that directly influences the level of organizational digital innovation success. Nevertheless, CIO structural power should not be overlooked because it could amplify (i.e., positively moderate) the impact of CIO issue selling to digital innovation outcomes. In addition, we identify four enabling forces of CIO issue selling effectiveness: (1) CIO strategic decision-making authority, (2) CIO/TMT partnership, (3) CIO information technologies (IT)–related strategic knowledge, and (4) CIO political savvy. Matched-pair survey data collected from senior business and IT executives of 179 organizations largely support the research hypotheses.

By filling the liquid crystal (LC) in the air holes of a photonic crystal fiber (PCF) with 8 mm length, a compact multi-band thermal optical switch is proposed here including two important telecommunication band, i.e., 1265 to 1317 nm and 1508 to 1568 nm. Within the bandwidth, the extinction ratio can be as high as 30 dB. Under the combined action of the bandgap-guiding mechanism and the interference effect, a temperature change of only 1 °C after clearing temperature ( Tc ) of the LC induces multi-band thermal optical switch of the LC-filled PCF. It is also noted that the transmission spectrum of the LC-filled PCF is quite sensitive to the ambient temperature. The consequent thermal sensitive is 3.9 nm/°C, making it a very good candidate for monitoring the temperature herein.

It is still a challenge to realize high mechanical and superior thermal conductive properties simultaneously in one thermal management material. Herein, chemically–physically double cross-linked and stretching orientation strategies were combined to construct a highly ordered cellulose nanofiber network and edge-hydroxylated boron nitride nanosheets (BNNS–OH) structure for fabricating robust cellulose/BNNS–OH composite film with superior thermal conductivity. The aligned regenerated cellulose nanofiber network induced the in-plane orientation of BNNS–OH through covalent and hydrogen bonding interaction. The air-drying densification process was further applied to construct a tightly packed structure for achieving a high tensile strength (226 MPa) and in-plane thermal conductivity (TC, 20.41 W m−1 K−1), which was almost 30 times higher than the through-plane TC (0.69 W m−1 K−1), indicating anisotropic TC properties. The flexible and robust composite film exhibited not only fast heat dissipation for cooling communication devices, but also superior oxygen barrier properties and signal penetration, showing its great potential in communication devices encapsulation. It also provides a novel avenue for preparing highly oriented one-dimensional and two-dimensional composite materials.

To further ascertain the origin of the Ordovician Majiagou Formation reservoirs in the Ordos Basin, the M54-M51 sub-members of the Ordovician Majiagou Formation in the eastern Sulige gasfield of Ordos Basin were taken as examples to analyze the vertical development characteristics of eogenetic karst and to discover the dissolution mechanism and its control on reservoirs through observation of a large number of cores and thin sections. According to detailed analysis of petrologic characteristics, the reservoir rock types include micritic dolomite, grain dolomite and microbialite which have mainly moldic pore, intergranular (dissolved) pore, and (dissolved) residual framework pore as main reservoir space respectively. The study area developed upward-shallowing sequences, with an exposure surface at the top of a single upward-shallowing sequence. The karst systems under the exposure surface had typical exposure characteristics of early dissolution and filling, indicating these reservoirs were related to the facies-controlled eogenetic karstification. With the increase of karstification intensity, the reservoirs became worse in physical properties.

Nitrous oxide (N2O), as one of the six greenhouse gases, is mainly produced in the biological nitrogen removal process of wastewater treatment plants (WWTPs). Establishing the N2O kinetic model can...

A “green”, low-cost, and efficient processing technology to spin regenerated cellulose multifilaments has attracted much attention in the textile field. Herein, robust cellulose filaments were prod...

The upgrading of tar is a key issue for the sufficient application of biowaste pyrolysis technology. Molten salt, with high migration and diffusion of ions to prevent the deactivation of coke deposition of tar reforming functional metals, is considered as a feasible catalytic reaction medium and heat carrier for the upgrading of tar. The present study investigated the interactions between small molecular pyrolysis gases (including H2, CO, CH4) and main tar model compound in ternary carbonate eutectics (Li2CO3–Na2CO3–K2CO3). The results demonstrated that H2 could be decomposed to produce H radicals, promoting the conversion of toluene into gaseous products. CO32− could consume H radicals required by toluene cracking, making the process toluene polymerized to polycyclic aromatic hydrocarbons be strengthened. On the other hand, CO would react with OH radicals to produce H radicals and could enhance gas-generating process. In addition, toluene could react with CO to form benzaldehyde and phenylacetaldehyde. With the addition of CH4, more H radicals were supposed to be consumed, and toluene cracking process was further inhibited. Finally, the effect sequence of small molecular gases (H2 > CH4 > CO) on toluene reforming reaction was authenticated by investigating the impacts of introducing any two gases in toluene reforming.

The present paper considers a fractional-order N species network, in which, the general functions are used for finding general theories. The existence, uniqueness, and non-negativity of the solutions for the considered model are proved. Moreover, the local and global asymptotic stability of the equilibrium point are studied by using eigenvalue method and Lyapunov direct method. Finally, some simple examples and numerical simulations are provided to demonstrate the theoretical results.

Co-pyrolysis of biomass with oxygen-lean polymer waste is a promising way to improve both quantity and quality of the derived oil. However, the release of sulfur contaminants causes serious adverse effects on the utilization of the derived oil. In order to promote the efficient and economic utilization of the derived products, the high-temperature desulfurization was conducted in this study using a ternary molten carbonates (Li2CO3–Na2CO3–K2CO3). And the effects of added Ca2+ or Cl−/SO42− on the desulfurization were estimated. The results demonstrated that the molten carbonates showed high efficiency in the removal of H2S/COS/SO2 at 500 °C. Alkali metals competitively reacted with H2S/COS to form various sulfides and sulfur species in the cooled products were probably determined by the crystallization processes. Besides, H2S removal was stimulated by adding CaCO3 and the formed CaS was precipitated from the molten salts. The addition of Cl−/SO42− changed the ion distribution characteristics of the molten salts and had slightly adverse effects on the removal of H2S. In contrast, SO2 removal was hardly affected while COS removal efficiency was decreased after adding Ca2+ or Cl−/SO42−. Anyway, the added Ca2+ favored the recovery of sulfur as well as the regeneration of spent molten carbonates.

The increasing penetration of renewable energy sources (RESs) brings more power generation fluctuations into power systems, which puts forward higher requirement on the regulation capacities for maintaining the power balance between supply and demand. In addition to traditional generators for providing regulation capacities, the progressed information and communication technologies enable an alternative method by controlling flexible loads, especially thermostatically controlled loads (TCLs) for regulation services. This paper investigates the modeling and control strategies of aggregated TCLs as the virtual energy storage system (VESS) for demand response. First, TCLs are modeled as VESSs and compared with the traditional energy storage system (ESS) to analyze their characteristic differences. Then, the control strategies of VESS are investigated in microgrid and main grid aspects, respectively. It shows that VESS control strategies can play important roles in frequency regulation and voltage regulation for power systems’ stability. Finally, future research directions of VESS are prospected, including the schedulable potential evaluation, modeling of TCLs, hierarchical control strategies of VESS considering ESSs and RESs and reliability and fast response in frequency control for VESS.

Strong near-field scattering enhancement (NFSE) of polyhedral oligomeric silsesquioxanes (POSS) nanoparticles (NPs) aggregates is found through physical simulation. An aggregation of N,N’-di-[3-(isobutyl polyhedral oligomeric silsesquioxanes) propyl] perylene diimide (DPP) which possesses POSS as scatteres experimentally performs strong NFSE, which confirms the physical simulation results. Moreover, coherent random laser is triggered from the DPP aggregates in carbon disulfide. It is the NFSE of POSS NPs connected to both ends of DPP through covalent bonds and the NFSE of their aggregation thanks to DPP’s aggregation that is responsible for the coherent random laser. So, this work develops a method to improve weak scattering of system through construction of molecules, and opens a road to a variety of novel interdisciplinary investigations, involving molecular designing for disordered photonics.Strong near-field scattering enhancement (NFSE) of polyhedral oligomeric silsesquioxanes (POSS) nanoparticles (NPs) aggregates is found through physical simulation. An aggregation of N,N’-di-[3-(isobutyl polyhedral oligomeric silsesquioxanes) propyl] perylene diimide (DPP) which possesses POSS as scatteres experimentally performs strong NFSE, which confirms the physical simulation results. Moreover, coherent random laser is triggered from the DPP aggregates in carbon disulfide. It is the NFSE of POSS NPs connected to both ends of DPP through covalent bonds and the NFSE of their aggregation thanks to DPP’s aggregation that is responsible for the coherent random laser. So, this work develops a method to improve weak scattering of system through construction of molecules, and opens a road to a variety of novel interdisciplinary investigations, involving molecular designing for disordered photonics.

We have demonstrated the realization of a coherent vesicle random lasing (VRL) from the dye doped azobenzene polymer vesicles self-assembled in the tetrahydrofuran-water system, which contains a double-walled structure: a hydrophilic and hydrophobic part. The effect of the dye and azobenzene polymer concentration on the threshold of random laser has been researched. The threshold of random laser decreases with an increase in the concentration of the pyrromethene 597 (PM597) laser and azobenzene polymer. Moreover, the scattering of small size group vesicles is attributed to providing a loop to boost the coherent random laser through the Fourier transform analysis. Due to the vesicles having the similar structure with the cell, the generation of coherent random lasers from vesicles expand random lasers to the biomedicine filed.

Exogenous metabolites from microbial and dietary origins have profound effects on host metabolism. Here, we report that a sub-population of lipid droplets (LDs), which are conserved organelles for fat storage, is defined by metabolite-modulated targeting of the C. elegans seipin ortholog, SEIP-1. Loss of SEIP-1 function reduces the size of a subset of LDs while over-expression of SEIP-1 has the opposite effect. Ultrastructural analysis reveals SEIP-1 enrichment in an endoplasmic reticulum (ER) subdomain, which co-purifies with LDs. Analyses of C. elegans and bacterial genetic mutants indicate a requirement of polyunsaturated fatty acids (PUFAs) and microbial cyclopropane fatty acids (CFAs) for SEIP-1 enrichment, as confirmed by dietary supplementation experiments. In mammalian cells, heterologously expressed SEIP-1 engages nascent lipid droplets and promotes their subsequent expansion in a conserved manner. Our results suggest that microbial and polyunsaturated fatty acids serve unexpected roles in regulating cellular fat storage by promoting LD diversity., Lipid droplets (LDs) are fat storage organelles that are initiated and expanded by seipins at ER contact sites. Here the authors show that the C. elegans seipin ortholog SEIP-1 is recruited to these sites by certain dietary fatty acids to support the expansion of a subset of LDs.

We develop a new reassembly pipeline that automatically restores an image from its rips. First, we develop an image fragment descriptor called Bundle-of-Superpixel, which can more effectively support the detection of correlated (adjacent) image fragments and the computation of local pairwise partial matching. We also develop a hierarchical global composition algorithm that iteratively performs the reassembly through a bottom-up manner. We also build a data benchmark for fragmented images and propose a set of quantitative recomposition assessment measures. Through extensive experiments and comparisons, we demonstrate the effectiveness of our proposed algorithms.

In this study, a new block-type rail bearing beam is presented, which consists of a cast-in-place base and prefabricated blocks. The finite element analysis is conducted to assess the proposed new rail bearing beam structure. The performed finite element method (FEM) simulation focused on the dynamic stress at the bottom of the rail bearing beam and structural internal force and deformation under the case of train loading, etc. Besides, the relationship between first-order natural frequency and activation frequency in the new support rail beam structure is analyzed and the beneficial effects on the internode connection structure are quantified. The results show that the increase in driving speed has the most significant effect on the vertical acceleration of the structure, and the self-vibration frequency of the structure is relatively large, which means the structure is safe. Since previous research seldom focuses on this block-type rail bearing beam, this study lays a valuable foundation for the construction of a rail bearing beam for the mid-low-speed maglev train.

The heterogeneity of the appearance and behavior of the crowd is an important component in a realistic simulation. Using Web3D technology to recreate a large-scale crowd of virtual avatars via the internet is an increasingly important area in crowd studies, especially for emergency crowd evacuation. One major issue in the early development of real-time simulation is the challenge of introducing diversity and authenticity on avatars’ appearance and behavior. Another major theoretical issue is high transmission delay on the network, which diminishes the simulation performed on the web browser when rendering a large number of visualization components. In this research, we propose a novel method to provide a lightweight solution that can simultaneously guarantee the realness and diversity of the simulated crowd. We use a parameterization technique based on shape space to distinguish the avatars’ appearance. Asynchronously transmitting the rendering elements helps to reduce bandwidth pressure. The multi-level clone instancing method can generate a massive amount of heterogeneous avatars in a short time. In the end, we validated our methods with an online experiment to demonstrate its ability to solve large-scale crowd simulation problems over the internet.

The rapidly increasing renewable energy sources (RESs) in the power system bring a large number of disturbances due to the intermittent and random characteristics of power generation. At the same time, most of the RES units are composed of power electronic devices, which can reduce the system inertia and impact the stable operation of the power system. Therefore, more operating reserve resources are required to participate in the rapid regulation in the power system with a high proportion of RES. The rapid development of information and communication technologies make it easier and lower cost to control flexible loads. Based on the new network resources, for example, 5G, flexible loads can be regulated rapidly to participate in power system frequency control. In this paper, the models, categories, and functions of typical flexible loads are analyzed. Then, the research status of various flexible loads for participating in frequency regulation (FR) is combed in detail. On this basis, the advantages and disadvantages of various load control methods and their application scenarios are discussed. Finally, the development prospects of flexible loads for FR are proposed, so as to provide references for practical application.

In recent years, machine learning, deep learning, neural network and other artificial intelligence technologies have made significant development and breakthroughs. Thus more mature and reliable technologies start to be applied in the field of data analysis. Data analysis is the process of studying and summarizing data in detail in order to extract useful information, that is, collecting, sorting, processing and analyzing data. Moreover, in order to make the analysis results easier to understand, data visualization technology is widely employed. This paper tries to review the state-of-the-art data analysis methods based on artificial intelligence. Besides, the mainstream data visualization technology and cases are elaborated. Finally, some open problems and challenges are also put forward for the future research.

In the past few years, the automatic construction of large-scale knowledge graphs has received extensive attention from academia and industry. In this paper, we show the specific applications and typical cases of knowledge graphs in data analysis, and summarize the overall process of knowledge graphs from construction to data analysis. Moreover, some open problems and challenges are also presented for the future research.

The Soil Conservation Service Curve Number (SCS-CN) method is widely used in conceptual rainfall-runoff models for describing the runoff response with a curve, which is a function of the cu...

With the development of the information and communication technologies, demand response (DR) can be realized more easily and considered as one of effective methods to provide regulation services for the power system. Among the flexible loads for DR, thermostatically controlled loads (TCLs) are regarded as one of the most important loads, because of the large share of power consumption and suitable regulation characteristics without impacting customers’ comfort. However, the dispatching potential of TCLs is difficult to be evaluated due to the limitation of measuring equipment. Faced with this issue, this paper proposes a method for evaluating the dispatching potential of TCLs based on the realistic customer electricity data in China. The relationship between the dispatching potential of TCLs and the ambient temperature is obtained. In this way, the system operator can calculate the dispatching potential of TCLs according to the weather forecast. The effectiveness of the proposed model and method is verified in the case studies.

Molten salt gasification is a promising way for collaborative use of solar energy and Zhundong coal, with in situ capture of Cl/S-pollutants as well as alkali metals. The present study provides a deep insight into carbon conversion during molten salt gasification of a typical Zhundong coal in ternary carbonate eutectics (Li2CO3-Na2CO3-K2CO3). The results demonstrated that the molten salt gasification of Zhundong coal underwent a rapid devolatilization of raw coal and then the gasification of char. The interactions between CO2 and volatiles promoted the cracking of macromolecular compounds, increasing the carbon conversion efficiency during the devolatilization process. The gasification of char was mainly determined by the direct reaction with molten salt, which was slightly affected by the CO2 concentration in the carrier gas. The results of char characterization evidenced that the condensation/graphitization of char was stimulated in the molten eutectics. Meanwhile, a large amount of O-containing groups, especially carbonyl groups, were formed in the molten salt treated char with carbonates as oxygen supplier. Under the influence of molten salts, some carbonyl groups would be formed inside the char. However, the decomposition of those carbonyl groups was suppressed by the mass transfer resistance of the released CO and/or CO2. Applying proper feeding mode, such as feeding coal in pulverized form, could enhance the contact of coal, molten salt and CO2, which remarkably promoted the interactions between molten salts and char containing functional groups.

Studies have employed various performance measures to determine the effect of virtual brand community (VBC) participation on customer values. However, different single-factor measures usually lead to conflicting results. This study proposes an overall participation performance measure, VBC participation performance, which follows a holistic-view definition of customer values, including frequency of customer visit, purchase frequency, purchase expenditure, and word-of-mouth frequency, obtain from the overall community activities, and it is evaluated through data envelopment analysis (DEA). We further determine the effect of the customer’s gender, age, tenure, and interactions on VBC participation performance by using Tobit regression models. The results show that our proposed measure outperforms either single-factor measures or measures based on other multicriteria decision analyses. Our findings also reveal that VBC is less efficient for females and customers with long tenure, and the effect of ge...

In recent years, potassium ion batteries (PIBs) with capacitor-like rate performance and battery-like capacity are highly desirable. To this aim, layered double hydroxides (LDHs) are studied in this work to evaluate the feasibility of employing LDHs as anode materials for PIBs. Our results show MgFe-LDH that contains trivalent iron cations with variable valence states can deliver K+-storage capacity of 371.6 mAh g–1 after running for 300 cycles at 0.1 A g–1 with an initial Coulombic efficiency of 88.4%. In contrast, MgAl-LDH that represents LDHs excluding multivalent metal elements merely delivers a capacity of 195.3 mAh g-1 under the same test condition but with a much higher initial Coulombic efficiency of 99.4%. Further study shows an electrical double layer effect is dominant to storing K+ for MgAl-LDH anode, while a faradaic process involving a conversion reaction between Fe3+ and Fe2+ is prevalent in MgFe-LDH anode. Rate performance of the MgFe-LDH/K cell shows its capacity retentions at 1, 2, 5, 10 A g–1 are 60.9%, 51.3%, 42.9%, 39.5%, respectively, which exhibit cause-effect relationships with its intrinsic poor conductivity and a non-efficient grinding event at high current densities. Besides, by measuring EIS spectra at different temperatures, the apparent activation energy is calculated to be 79.5 kJ mol–1. It is thus anticipated that this study will shed new light on developing LDHs as powerful anode materials for PIBs.

We have demonstrated a low threshold and tunable flexible random laser (RL) in dye-doped poly ethylene glycol diacrylate (PEG-DA) hydrogel, which was prepared by crosslinking polymerization using PEG-DA monomer and photoinitiator. The random lasering is attributed to the light scattering from the porous structure of hydrogels, and the wavelength of random lasing can be tuned by ~3.2 nm in the temperature range from 30 °C to 70 °C. Under the continuous increasing and decreasing temperature cycle, the random lasing tunable phenomenon can still be observed, which proves that this flexible material can be used as a new temperature sensor. In addition, we also explored the application of flexible laser in phototherapy. Considering the good elasticity and transparency of hydrogels, this thermo-responsive property will be of great significance to the biomedical applications of flexible material.

Magnesium ammonium phosphate (MAP) crystallization could be utilized for the recovery of phosphorus from wastewater. However, the effectiveness of the recovery is largely determined by the crystallization process, which is very hard to be directly observed. As a result, a specific ultrasonic device was designed to investigate the crystallization characteristics of MAP under various ultrasonic conditions. The results demonstrated that the metastable zone width (MZW) narrowed along with the rising of the ultrasonic power. Similarly, for the 6mM MAP solution, with the ultrasonic power gradually enhanced from 0W to 400W, the induction time was shortened from 340s to 38s. Meanwhile, the crystallization rate was accelerated till the power reached 350W, and then remained a constant value. It can be observed from the scanning electron microscopy (SEM), the MAP crystal became bigger in size as well as the crystal size distribution (CSD) became broad and uneven, with the increase of ultrasonic power. The results indicate that the crystallization process enhanced by power ultrasound could be used as an effective method to eliminate and recover the phosphorus from wastewater.

Based on stimulated Brillouin scattering (SBS), the slow light effect in photonic crystal fibre (PCF), which is filled with highly nonlinear liquid-carbon disuphide in the core region, is investigated. Maximum allowable pump power for undistorted output pulse, minimum value of pump power required to initiate the SBS effect, Brillouin gain and time-tonic delay experienced by the pulse in the designed liquid-core photonic crystal fibre, are all calculated numerically. We have found that the maximum time-delay up to ∼134.4 ns at 1.064 μm can be obtained using 1 m long liquid-core PCF pumped with only 65.8 mW, which is lower than the value reported in the literature for achieving such a high delay time. The results indicate that liquid-core PCF is capable of generating tunable time-delay that is adjusted by the pump power and structural parameters of the proposed liquid-core PCF.

Thermal treatment could effectively realize the detoxification of heavy metals in municipal solid waste incineration (MSWI) fly ash through the approach of removal or stabilization process. To lower the operating temperature and suppress the evaporation of heavy metals, a molten salts (NaCl-CaCl2) thermal treatment method was proposed for the detoxification of heavy metals from MSWI fly ash at a relatively mild condition (600/800 °C). The fate of heavy metals during the heating process and their stabilization properties in the remained ash slag after molten salts thermal treatment were investigated. The results showed that, compared with the traditional thermal treatment, heavy metals were more easily chlorinated by the means of molten salts thermal treatment. The well distributed chloride in molten salts facilitated the direct chlorination of PbO/CdO. Furthermore, Al2O3 in ash enhanced the indirect chlorination of CuO/PbO/CdO, except for ZnO. In contrast, SiO2 showed better performance in promoting the indirect chlorination of heavy metal oxides. Meanwhile, some Zn2+ was precipitated from molten salts as Si/Al-Zn composite oxides through the interactions with ash containing Si/Al oxides. On the other hand, the dissolved heavy metals in molten salts showed a good thermal stability during the thermal treatment. The volatilization fractions of all detected heavy metals were less than 5%. After the molten salts thermal treatment, heavy metals in the ash slag were well stabilized and the amount of heavy metals leached was significantly lower than that from the raw fly ash.

Programmable materials and reconfigurable photonic components, which can change their physicochemical properties and functionalities upon external stimuli, are a major topic of interest in modern science. However, most conventional reconfigurable photonic components rely heavily on mechanical deformation, restricting their application. Herein, a novel strategy based on a dynamically tunable fluorescence resonance energy transfer process to design and fabricate programmable fluorescent micropatterns within single polymer microfiber is proposed. A set of reconfigurable photonic components (including optical switchable waveguide systems, photonic analogies of diodes and transistors, as well as one-dimensional (1D) optical encoding) can be achieved within a single polymeric waveguide microfiber straightforwardly, in which such photonic components can be written, erased, and rewritten as 1D binary patterns with tailored external optical stimuli. These results might be of great fundamental value for the rational design of novel reconfigurable photonic devices with numerous potential applications in highly integrated optical communication components and optical computing devices.

A laboratory-scale biological aerated filter (BAF), using volcanic scoria particles (VSP), was used for treating micro-polluted source water. The system reached a steady-state stage and performed better at removing pollutants. In steady-state stage, the effluent ammonia ( NH4+-N ) and chemical oxygen demand (COD) were consistently maintained below 0.3 and 3 mg/L, respectively. Both the NH4+-N and COD removal efficiencies decreased with shorter hydraulic retention time (HRT). The effluent NH4+-N and COD exceeded health standards at 15 min of HRT. Although performance was relatively poor for VSP-BAF at low temperature, the NH4+-N removal still achieved the drinking water quality standard. The influences of influent NH4+-N and COD concentration changes were similar to that of temperature. A better performance was observed in NH4+-N removal under higher influent NH4+-N concentrations. In contrast, the effluent COD was more than 3 mg/L when the influent COD concentrations increased to about 9 mg/L. The phylogenetic and cluster analyses indicated that the effect of HRT on bacteria community structure was higher than that of temperature, while the ammonia-oxidizing bacteria (AOB) are sensitive to temperature. The main phyla identified in total bacteria communities were Proteobacteria, Bacteroidetes, Firmicutes, and Nitrospirae. The main AOB were Nitrosomonadales and an uncultured ammonia-oxidizing bacterium. PRACTITIONER POINTS: The BAF using VSP obtained a good performance for treating micro-polluted source water. The influence of HRT on the system was more significant than that of temperature. The system is resistant to NH4+-N concentration shocks while is unable to withstand the COD increasing. The effect of HRT on bacteria community structure was significantly higher than that of temperature.

N2O (Nitrous oxide) is a strong greenhouse gas, and wastewater treatment process is one of the important artificial sources of N2O. Controlling N2O production and discharge in wastewater treatment process is beneficial to alleviate the greenhouse effect. Based on the mechanism of N2O production in biological nitrogen removal process, emission characteristics and influencing factors of N2O in three traditional biological nitrogen removal processes, A/A/O, SBR and oxidation ditch, and two new biological nitrogen removal processes, SBBR and CANON, have been reviewed. Furthermore, a control strategy for slowing the generation and release of N2O is proposed, which provides a reference for researchers in related field.

Electrospinning is a very simple method of preparing polymer solutions into high performance fibers. In this work, PM597-doped polymer fibers with different diameters have been fabricated by electrospinning technology. Whispering gallery mode (WGM) lasing emission was observed when a 532 nm pulse laser beam radially excited the single electrospun polymer fiber (EPF) created by this method. The distribution of WGMs is also quantitatively confirmed through theoretical calculation. Additionally, the number of WGM laser peaks decrease as the diameter of the EPF decreases. Single longitudinal mode laser emission can be obtained when the EPF diameter decreases to 8.8m. It has also been found that the WGM laser from the single EPF has relatively low thresholds and good lifetime compared to droplet lasers or other fiber lasers. Moreover, EPF networks have unique research prospects in photonic devices, optical pump lasers and biosensing due to their very large surface to volume ratio.

Electrically responsive photonic crystals represent one of the most promising intelligent material candidates for technological applications in optoelectronics. In this research, dye-doped polymer-stabilized cholesteric liquid crystals (PSCLCs) with negative dielectric anisotropy were fabricated, and mirrorless lasing with an electrically tunable wavelength was successfully achieved. Unlike conventional liquid-crystal lasers, the proposed laser aided in tuning the emission wavelength through controlling the reflection bandwidth based on gradient pitch distribution. The principal advantage of the electrically controlled dye-doped PSCLC laser is that the electric field is applied parallel to the helical axis, which changes the pitch gradient instead of rotating the helix axis, thus keeping the heliconical structure intact during lasing. The broad tuning range (∼110 nm) of PSCLC lasers, coupled with their stable emission performance, continuous tunability, and easy fabrication, leads to its numerous potential applications in intelligent optoelectronic devices, such as sensing, medicine, and display.

Graphene nanosheet (GNS) films exhibit good thermal and electric conductivities due to low oxygen content and defect density. However, the weak interlayer interaction forces have resulted in poor mechanical properties and flexibility for GNS films. In order to meet this challenge, aramid nanofiber (ANF) is introduced into the GNS films by solution mixing, then a small amount of water is added to adjust the aramid nanofiber framework (ANFF) in the solution. The results indicate that adding a small amount of water into the aramid nanofiber/dimethyl sulphoxide (ANF/DMSO) suspension can recover the hydrogen bonds between ANF, promoting the ANF to form a stable framework. This design strategy leads to a delectate balance between flexibility and electric, thermal conductivities. With the improvement of water or ANFF content, the mechanical properties of GNS/ANFF composite films are gradually increased. And the electric and thermal conductivities are not influenced by the water content but decrease with the increasement of ANFF content. Most importantly, the flexibility of GNS films is greatly improved with little sacrifice of electric and thermal conductivities by adding only 2 wt% ANFF (GNS-2). The tensile toughness of GNS-2 composite films is dramatically improved from 30.8 to 108.7 kJ m−3, while the electric and thermal conductivities of GNS films are slightly dropped from 827 to 569 S cm−1 and from 140 to 131 W m−1 K−1, respectively. Moreover, the excellent flexibility of the composite films can be maintained even after 1000 times of direct bending. The good over-all properties together with its easy preparation process endows GNS/ANFF composite films with potential applications in next-generation flexible electric devices.

The low-temperature alkali/urea aqueous system has received wide public attention since it is a better method to reduce pollution by preparing the regenerated cellulose fiber through the green dissolution system. Since molecular weight has a significant impact on the solubility and mechanical property of regenerated cellulose fiber; thus, we designed this experiment that cellulose materials with molecular weight ranging between 6.8 × 104 to 13.5 × 104 were employed for wet-spinning in alkali/urea aqueous system. It is found that as molecular weight of cellulose increases, cellulose solution decreases in solubility but cellulose molecular chain aggregates increase. However, bath the stability and viscosity of cellulose solutions almost remain unchanged with the change of molecular weight. As for the spun fibers, it is found that the orientation and crystallinity are relatively high when the molecular weight is low (6.8 × 104–9 × 104). These are excellent mechanical properties However, unlike conventional polymers, when molecular weight further increases to 9 × 104–13.5 × 104, the degree of orientation and crystallinity gradually decreases. This is due to a large number of entanglements between adjacent molecular chains, thereby hindering the molecular chain orientation along with reduced mechanical property. Our work demonstrates that the considerable molecular weight of cellulose is neither good for dissolution nor spun fibers' mechanical property. The choice of cellulose with relatively low molecular weight is essential not only for the excellent dissolution but also for fiber property.

Boundary control for a class of partial integro-differential systems with space and time dependent coefficients is considered. A control law is derived via the partial differential equation (PDE) backstepping. The existence of kernel equations is proved. Exponential stability of the closed-loop system is achieved. Simulation results are presented through figures.

Quenching-partitioning-tempering (Q-P-T) process was used to treat a Ti-microalloyed low-carbon stainless steel after cold rolling. In addition to martensite, ferrite and retained austenite, TiN, coarse TiC, fine TiC, (Fe,Cr)3C and ultra-fine TiC precipitates were formed after the Q-P-T treatment. Based on field emission-scanning electron microscope (FESEM) and transmission electron microscope (TEM) observations, thermodynamic, crystallographic and statistical analyses were used to reveal the precipitation behaviors of these particles. The effects of partitioning-tempering (P-T) temperature and time on the microstructure and mechanical properties of Q-P-T treated specimens were specially studied. The coarsening and spheroidization of (Fe,Cr)3C particles during P-T stage were obviously retarded by large Cr addition. The retained austenite was obtained significantly with appropriate P-T parameters. The precipitation of ultra-fine TiC particles in the martensite during the P-T stage at 500 °C induced a secondary hardening.

Ba0.6Sr0.4TiO3 (BST) thin films were deposited on Pt/Ti/SiO2/Si substrates by a RF-magnetron sputtering. The film crystallinity was influenced by the in situ heat treatment. The surface images, dielectric and ferroelectric properties of the thin films were investigated. The BST thin films deposited at 400°C were crystallized after heat treatment over 500°C for 20 minutes. The high dielectric constant of 320 and dielectric tunability of 30% was achieved in the BST thin films while the dielectric loss was less than 0.05 by adjusting the annealing temperature. And the thin films exhibited strong ferroelectric property when the film thickness was over 90 nm.

An asymmetrical dual-core photonic crystal fiber (DC-PCF), which possesses all circular air holes, is proposed. By setting appropriate geometrical parameters, the wavelength-selective coupling property is realized, and a compact optical filter with a short length of 1.83 mm based on the DC-PCF is designed. The spectral transmission characteristics of the filter are investigated by the beam propagation method. The results demonstrate that the optical filter possesses a bandwidth of ∼ 58 nm and small sidelobes. The proposed optical filter could be used in the integrated optical systems.

This work systematically illustrated the effects of solvents on random lasing in active scatterer solution systems. The scatterer, N,N′-di[3-(isobutyl polyhedral oligomeric silsesquioxanes)propyl]perylene diimide (DPP), was chemically synthesized from gain group perylene diimide (PDI) and scattering group polyhedral oligomeric silsesquioxanes (POSS) at a mole ratio of 1:2 through chemical bonding. Random lasing action was detected in such solutions with a series of solvents ordered by refractive index (RI), from which it was found that solution systems with larger RI solvent facilitate boosting of random laser (RL) for a suitable “Δl = ls − lg” (ls > lg). There are two potential situations for solvents with smaller RI: in one, a small RI difference between scatterers and surroundings results in extremely large ls, and the extremely large Δl in these samples means that there is no observation of random lasing; in the other, there is increased lg as characterized by UV-Vis spectroscopy, although the ls remains almost unchanged for the large RI fluctuations between scatterers and surroundings, resulting in smaller Δl with no detection of random lasing as the laser pumping energy cannot compensate for the gain loss. Results from this work will aid in quantitatively judging the necessary condition of “Δl = ls − lg” to RL in solutions, and aid in designing suitable solution systems to boost RL.

Nano-scale aggregates of hybrid molecules, such as N,N′-di-[3-(isobutyl polyhedral oligomeric silsesquioxanes)propyl] perylene diimide (DPP) which is composed of perylene diimide (PDI) as gain group and polyhedral oligomeric silsesquioxanes (POSS) as scattering group at a mole ratio of 1:2, are formed in carbon disulfide (CS2) solution within a concentration range from 3 × 10−5 M to 10−3 M. The aggregation of DPP in the solution was characterized using ultraviolet visible (UV-vis) and fluorescence spectroscopy. Under pumping of a 532 nm pulse laser, coherent random laser (RL) is produced from the aggregates in CS2 solution with a threshold of 17.4 μJ and a Q value of 2440 at a DPP concentration of 10−4 M. Enhanced near zone scattering by aggregation is thought to boost coherent RL. This research not only extends the RL system to the extremely weak scattering regime but also provides a new direction for research on nano-scale materials for lasers using molecular design.

A reconfigurable photonic fractional Fourier transformer is proposed to realize broadband frequency measurement and large-scale chirp rate characterization of microwave signals with a high resolution. This scheme is based on three parallel frequency-shifting loops (FSLs) with co-prime free spectral range (FSR). Tunable high-resolution fractional Fourier transform is achieved through simply changing the frequency shift in each FSL with a small FSR, and large unambiguous frequency and chirp rate measurement range are guaranteed by the proposed recovery algorithm. In the numerical verification, non-aliasing frequency measurement range up to 14.7404 GHz and unambiguous chirp rate characterization range from -4.35 × 105 to 4.35 × 105 GHz/ μ s are obtained by using three FSLs with FSRs of 17.13 MHz, 17.21 MHz and 17.39 MHz, where the frequency resolution and the chirp rate resolution are 139.12 kHz and 0.3356 GHz/ms, respectively. Through properly setting the FSR in each FSL, the frequency and chirp rate measurement range can be further improved, which can find application in electronic warfare to achieve microwave signal recognition.

In this paper, pure silk protein was extracted from Bombyx mori silks and fabricated into a new kind of disordered bio-microfiber structure using electrospinning technology. Coherent random lasing emission with low threshold was achieved in the silk fibroin fibers. The random lasing emission wavelength can be tuned in the range of 33 nm by controlling the pump location with different scattering strengths. Therefore, the bio-microfiber random lasers can be a wide spectral light source when the system is doped with a gain or energy transfer medium with a large fluorescence emission band. Application of the random lasers of the bio-microfibers as a low-coherence light source in speckle-free imaging had also been studied.

The disposal of the hazardous municipal solid waste (MSW) incineration fly ash is a critical environmental issue in China and the high contents of salts in the fly ash make the ash disposal extremely difficult. The present study proposes a novel method for the salts removal from MSW incineration fly ash using molten carbonates and chlorides at moderate temperatures from 773 K to 1073 K. The results showed that molten salts could effectively extract alkali and alkaline earth metals chlorides and sulfates from the fly ash. Other ash components, like Si/Al-compounds, were precipitated from the molten salts and concentrated in residues. By comparison, molten carbonates showed greater capability in the salts extraction while molten chlorides showed better selectivity in chlorides removal from MSW incineration fly ash. These findings suggest that the optimization of molten salts system could further prove the potential applicability of molten salts thermal treatment method for the salts removal from MSW incineration fly ash.

We report on the detailed analyses of mode coupling from fiber core to cladding in excessively tilted fiber gratings (ETFGs). Cladding modes responsible for the typical dual peak pairs in the transmission spectrum of ETFGs are identified with phase matching condition, which suggests two set of dual peak pairs generated from coupling to cladding modes with even and odd azimuthal order. The polarization dependence of those dual peak pairs are also investigated by calculating the coupling coefficients of cladding modes for two orthogonal polarizations. With the calculated coupling coefficients, the measured polarization dependent spectra can be reproduced numerically.

This paper proposes state-of-charge (SOC) balancing control based on discrete consensus algorithm to improve the accuracy of power dispatch of the battery energy storage systems (BESS), reducing system cost and prolong the service life of the BESS in islanded microgrid. This has been achieved with hierarchical distributed secondary cooperative control based on discrete consensus algorithm, which modifies the BESS output power to reach a balanced SOC. The control structure has two layers. The cooperative control works as the secondary layer, obtaining equal SOC of the BESS of the grid through interchanges information of energy storage systems state of charge (SOC) with its neighbors. BESS control approach as the primary control layer, they are able to realize the output power sharing and the balancing discharge rate by regulating the virtual resistance. The simulation platform is built based on Matlab/Simulink software. The validity and feasibility of the proposed control strategy has been further verified by various simulation results.

Arsenic is easily volatilized as vapors during coal combustion and predominantly transferred into particulate forms. The removal of particulate arsenic together with fine fly ash particles is essential to control arsenic emission during coal combustion. In this study, fly ashes and different size fraction samples (PM2.5, PM10, and PM20) were collected or prepared from four Chinese coal-fired power plants, with objectives of studying the arsenic distribution and speciation in fly ash, and understanding the retention relationship between the removal of ash particles and particulate arsenic. The results demonstrated that the concentration of arsenic of the first two ESP (electrostatic precipitator) hoppers was at similar level, then followed by a substantial increase in the rear hoppers. And the particle size distribution of fine fly ash particles from various ESP systems presented essentially similar trend. Furthermore, particulate arsenic was mainly present as arsenates probably through the interactions between arsenic vapors and accessory Ca/Fe/Al-minerals. Arsenic associated with calcium compounds tended to be enriched in coarse particles, while arsenic bound with Fe/Al-compounds was enriched in fine particles. Meanwhile, arsenic associated with calcium sulfate compounds was easier to be captured by ESP compared to calcium silicate-bound arsenic. The interactions between arsenic vapors and various accessory minerals not only affected the size distribution characteristics of particulate arsenic, but also had a great effect on its removal efficiency of ESP. Specifically, based on the ash resistivity calculation, arsenic-bearing fine particles with certain amount of Fe had suitable conductivity and favored the capture of particulate arsenic by ESP.

One critical challenge of today's cloud services is how to provide an effective search service while preserving user privacy. In this paper, we propose a wildcard-based multi-keyword fuzzy search (WMFS) scheme over the encrypted data, which tolerates keyword misspellings by exploiting the indecomposable property of primes. Compared with existing secure fuzzy search schemes, our WMFS scheme has the following merits: 1) Efficiency. It eliminates the requirement of a predefined dictionary and thus supports updates efficiently. 2) High accuracy. It eliminates the false positive and false negative introduced by specific data structures and thus allows the user to retrieve files as accurate as possible. 3) Flexibility. It gives the user great flexibility to specify different search patterns including keyword and substring matching. Extensive experiments on a real data set demonstrate the effectiveness and efficiency of our scheme.

Trapping light within cavities or waveguides in photonic crystals is an effective technology in modern integrated optics. Traditionally, cavities rely on total internal reflection or a photonic bandgap to achieve field confinement. Recent investigations have examined new localized modes that occur at a Dirac frequency that is beyond any complete photonic bandgap. We design Al2O3 dielectric cylinders placed on a triangular lattice in air, and change the central rod size to form a photonic crystal microcavity. It is predicted that waves can be localized at the Dirac frequency in this device without photonic bandgaps or total internal reflections. We perform a theoretical analysis of this new wave localization and verify it experimentally. This work paves the way for exploring localized defect modes at the Dirac point in the visible and infrared bands, with potential applicability to new optical devices.

The stability of the scattering loop is fundamental for coherent random lasing in a dynamic scattering system. In this work, fluorescence of DPP (N, N-di [3-(isobutyl polyhedral oligomeric silsesquioxanes) propyl] perylene diimide) is scattered to produce RL and we realize the transition from incoherent RL to coherent RL by controlling the Brownian motion of the scatterers (dimer aggregates of DPP) and the stability of scattering loop. To produce coherent random lasers, the loop needs to maintain a stable state within the loop-stable time, which can be determined through controlled Brownian motion of scatterers in the scattering system. The result shows that the loop-stable time is within 5.83 × 10−5 s to 1.61 × 10−4 s based on the transition from coherent to incoherent random lasing. The time range could be tuned by finely controlling the viscosity of the solution. This work not only develops a method to predict the loop-stable time, but also develops the study between Brownian motion and random lasers, which opens the road to a variety of novel interdisciplinary investigations involving modern statistical mechanics and disordered photonics.